1. Field
The present invention relates to animal spray systems and more particularly to such systems designed to wash the udders of cows prior to milking.
2. Prior Art
In prior art systems, the udders of milk cows are typically washed with water prior to milking by means of an elevated spray head. In such systems, the spray head, such as spray head 14 shown in FIG. 9, is raised 8 to 10 inches above floor level by mounted the spray head on top of a vertically positioned pipe, such as pipe 13, also shown this Figure. The spray head is positioned close to the udders by means of the vertical pipe to prevent the spray emanating from the head from missing the udders. Water is supplied to the vertical pipe and the spray head from a water main 11 located below the vertical pipe.
The spray produced by prior art spray head is primarily in the form of a plurality of distinct small streams each emanating from a separate hole in the spray head. The individual streams spread apart from one another as they travel away from the spray head. To insure the spread between streams is small and covers most of the average udders when the streams reach the udders, they are brought close to the utters by raising them above floor level. If the prior art spray heads were positioned instead close to the floor level with their divergent streams aimed at the average udder, then the probability is increased that some of the individual streams could miss a part or all of the udders because of the distance to the udders, the difference in individual udders and the varying position of the cows with respect to the spray head as the cows pass over the spray head.
A prior art spray head 16 is shown in plan view in FIG. 11A and in elevation in FIG. 11B. The spray head 16 includes a vertical side 16A and a chamfered side 16B. There are four hole 17A through 17D located on the chamfered side. Each hole produces an individual stream which is directed upwards and to the side of the head, creating the divergence between the streams as they travel further from the head.
An alternate to placing the holes on the chamfered side is to place them on the top surface 16C of the spray head, but to angle the holes away from the center of the head to provide some distance between the individual streams to prevent all the streams from spraying the water at a single location. The results are similar to placing the holes on the chamfered surface. The individual streams spread apart as the travel away from the head and can contribute to a stream missing all or part of the udders.
Regardless of how these streams are aimed, it is difficult to provide a spray head of this type located near floor level which covers the udders well because the udders of different cows are at different heights. Coverage of the udders with individual streams is in part achieved by the spattering of the streams once they hits the utters; however, spattering is not a completely satisfactory method of washing because it uses partly contaminated water to wash the parts of the udders not hit directly by a stream. To effect the spattering, the streams must remain at a relatively high pressure level when they hits the udders. To insure that this relative high pressure is achieved, the spray heads are positioned close to the utters.
This is a second reason for the raised height of the prior art spray heads and it is precisely this height that presents one of the greatest problem encountered with this prior art system. The vertical pipes are the cause of thousand of dollars of injuries occurring presently on thousand of farms throughout the country. These injuries are caused by the cows kicking and stumbling over the vertical pipes. Many of the areas in which these prior art system are installed are filled with multiple heads and with multiple vertical pipes to insure that the cows are washed thoroughly; however, the multiple vertical pipes only multiply the chances of incurring injury.
The vertical pipes and the tendency of the cows to kick the vertical pipes has prompted users of these systems to install cow guards, such as cow guard 27 which is mounted about prior art spray head 14 and vertical pipe 13 as shown in FIGS. 16A and 16B.
FIG. 16A is approximately full scale while FIG. 16B is reduced scale to permit showing the relative height of the vertical pipe 13 with respect to the cow guard 27. The cow guard is typically a section of four inch diameter pipe cut in four inch lengths and welded to the water main about the junction of the pipe 13 to prevent cows from kicking, bending and eventually breaking off the pipe 13 from the water main.
Unfortunately the cow guard causes as much injury and in many cases more serious injury than the vertical pipes do. The cows can have the hoofs cut off while walking over the cow guards because the edges of the guards become sharp as the sides of the guards are continually brushed by the cows hoofs. A cow can step on top of the sharp guard and then have another cow step on her hoof causing the severing of the hoof. This is extremely upsetting to the rancher who owns the cows because he does not want the cows to suffer in this way and also because it represents a serious financial loss.
As noted above, the financial loss to those in milk producing industry can be highs but the extent of that loss comes into clearer view when specific costs are considered. The cost of a replacement cow is typically $1,200. The loss of 2 percent per year of 1,000 head is 20 head or $24,000 per year. Replacement of heads and pipes in prior art systems, which can last as little as three months, add approximately $1,000 more in cost per year for a total of $25,000 a year.
There is currently a serious need in the milk producing industry for a new spray head which presents a low profile and entirely eliminates the vertical pipes and the cow guards to reduce the present high cost of injuries incurred with the prior art spray system. Despite the lower pressure and greater distance of lowered spray head, any system incorporating lowered spray heads to be successful must overcome these problems and be capable of thoroughly washing the entire udders.